essentially mr. romney has to tell the world how will he grow america's economy compared to the miserable rate of growth that we've had for the last three and a half years. >> reporter: it's going to be an interesting debate tomorrow night. thank you so much. the president and governor romney may be taking time off the campaign trail today for debate practice but the vice presidental candidates are not. vice president joe biden spoke to voters in charlotte, north carolina a short time ago about the concerns he has over his opponent's plan for medicare, while at wong man's paul ryan's event in iowa today things took an emotional term when a veteran asked him about his social security benefits and why the government taxes the only source of income for a man who dedicated his life to defending his country. >> i served in the air force in 65 straight out of high school, and i learned in the military -- [applause] >> -- the skills that i had to take me through life. i served in grenada, and i served in ir